Whitney played Yeoman Janice Rand in the first eight episodes of the series, and then was written out of the show. In her autobiography The Longest Trek: My Tour of the Galaxy, she said that her acting career ended after that and she became an alcoholic.

After seeking treatment, Leonard Nimoy helped her resurrect her career.

She reprised her role in Star Trek: The Motion Picture, Star Trek III: The Search for Spock, Star Trek IV: The Voyage Home and Star Trek VI: The Undiscovered Country.